The invention relates to photography and photographic equipment and methods and more particularly relates to an underwater camera having viewports supported by an internal camera assembly frame.
Underwater cameras and housings must make provisions to compensate for the compressing effects of water pressure during use. With one-time-use underwater cameras, there is a further constraint, and that the features provided to handle water pressure must not make the camera too cumbersome for use above water. A past approach has been the inclusion of rigid support structures in portions of the camera where compression would otherwise interfere with a camera function.
U.S. Pat. Nos. 5,689,735 and 5,729,769 disclose underwater one-time-use cameras in which structural protrusions or ribs are used to prevent water pressure from compressing a housing so as to pinch film against the inside of a rear cover.
Japanese patent publication JP 11-194414, published Jul. 21, 1999, discloses a waterproof one-time-use camera in which frame reinforcements support a cover/housing. The waterproof front cover/housing is transparent and incorporates a front viewfinder lens and a separate rear viewfinder lens is mounted in the rear cover/waterproof housing or the rear cover/housing incorporates the rear lens.
U.S. Pat. No. 4,882,600 teaches an underwater one-time-use camera having an inner frame assembly that is covered by a paper-cardboard sealed pack and then a waterproof housing. The housing is transparent and front and rear lenses of a viewfinder are formed as part of the housing. The frame assembly and cardboard pack have openings defining the viewfinder and the lenses are aligned with the openings. A lens can extend into a respective opening. The tunnel of the viewfinder, as shown, is part of the front cover of the frame assembly. The lenses of the housing are illustrated as bearing on the cardboard pack and, through the pack, on the tunnel of the front cover. Alternatively or additionally, the lenses bear on areas of the front cover in spaced relation to the viewfinder tunnel. This approach requires that the front cover have strength in the area of the viewfinder tunnel, or the alternative areas, sufficient to resist compressive forces.
It would thus be desirable to provide an improved camera and method in which the frame bears part of the compressive load directly, rather than through the covers.
The invention is defined by the claims. The invention, in broader aspects, provides an underwater camera has a frame assembly, which has a frame and front and rear covers mounted on the frame. The frame has a viewfinder tunnel. A pressure housing has an internal cavity holding the frame assembly. The pressure housing has opposed first and second viewports. The viewports each bear directly on the viewfinder tunnel and are disposed in non-load-bearing relation to said covers.
It is an advantageous effect of the invention that an improved camera and method are provided, in which the frame bears part of the compressive load directly, rather than through the covers.